(1) Technical Field
The present disclosure relates to organic electroluminescence (EL) elements that use electroluminescence of organic material, organic EL display panels that use the organic EL elements, and organic EL display panel manufacturing methods.
(2) Description of Related Art
In recent years, as display panels used in display devices such as digital televisions, organic EL display panels are being implemented in which a plurality of organic EL elements are arrayed in a matrix on a substrate. Such organic EL display panels have high visibility, because each organic EL element is self-luminous.
In an organic EL display panel, each organic EL element typically has a structure in which a light-emitting layer that includes an organic light-emitting material is disposed between an anode and cathode pair of electrodes. When driven, a voltage is applied between the pair of electrodes, holes are injected to the light-emitting layer from the anode, electrons are injected to the light-emitting layer from the cathode, and the holes and the electrons recombine to emit light.
In the organic EL display panel, light-emitting layers are typically separated from adjacent organic EL elements by banks composed of an insulative material. In an organic EL display panel for color display, such organic EL elements form RGB color pixels, one pixel in a color display being formed by a combination of adjacent RGB pixels.
Typically, in an organic EL display panel, in order to prevent leaking of light between adjacent pixels and mixing of colors of light associated with this, a lattice-shaped light-shielding layer is provided above the banks at boundaries between adjacent pixels. For example, WO 2013108783 discloses an organic EL element that suppresses a decrease in aperture ratio while also preventing color mixing between adjacent pixels, by using a matrix-shaped light-shielding member that has different thicknesses above a color filter substrate. Further, JP 2015-72827 discloses an organic EL display device that has an element substrate on which a light-emitting layer and a light-shielding member are disposed, and has a color filter layer that includes colored layers of multiple colors and an inter-pixel light-shielding member between colored layers. The light-shielding member is disposed more centrally in each pixel than the inter-pixel light-shielding member and thereby suppresses parallax mixed color due to light leakage to adjacent pixels and obtains high light extraction efficiency.